add: 久坐提醒项目文件

AppSettings.cs

@@ -0,0 +1,46 @@
+using System;
+using System.IO;
+using System.Text.Json;
+
+namespace TimerApp
+{
+    public class AppSettings
+    {
+        public int WorkMinutes { get; set; } = 20;
+        public int RestMinutes { get; set; } = 1;
+        public int IdleThresholdSeconds { get; set; } = 30;
+        public bool IsDarkMode { get; set; } = true;
+
+        private static string ConfigPath => Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "settings.json");
+
+        public static AppSettings Load()
+        {
+            try
+            {
+                if (File.Exists(ConfigPath))
+                {
+                    string json = File.ReadAllText(ConfigPath);
+                    return JsonSerializer.Deserialize<AppSettings>(json);
+                }
+            }
+            catch
+            {
+                // ignore errors, return default
+            }
+            return new AppSettings();
+        }
+
+        public void Save()
+        {
+            try
+            {
+                string json = JsonSerializer.Serialize(this, new JsonSerializerOptions { WriteIndented = true });
+                File.WriteAllText(ConfigPath, json);
+            }
+            catch
+            {
+                // ignore
+            }
+        }
+    }
+}